Routine work and periodic work have different constraints
A nightly office attendance in a tower is largely self-contained. Equipment lives in the tenancy store, the cleaner arrives through the normal after-hours entry, and the only external dependency is that the floor is released on time and the lifts are running. Scheduling that is mostly a matter of agreeing an hour with the tenant, confirming the security arrangements and recording who is notified when something needs attention.
Periodic work breaks all of those assumptions at once. Extraction equipment has to come in through the dock, travel in a goods lift and often needs a longer access window than the routine attendance. If the schedule treats a periodic task as though it were a longer version of a nightly one, the date will be set and then missed because nobody booked the lift.
